cleansys-core 0.6.2

use anyhow::{Context, Result};
use colored::*;
use std::io::{self, Write};
use std::process::Command;
#[cfg(unix)]
use users::get_effective_uid;

/// Check if the program is running with root privileges (Unix) or an
/// elevated/Administrator token (Windows).
#[cfg(unix)]
pub fn check_root() -> bool {
    get_effective_uid() == 0
}

/// Check if the current process token is elevated (running "as Administrator").
#[cfg(windows)]
pub fn check_root() -> bool {
    is_elevated::is_elevated()
}

#[cfg(not(any(unix, windows)))]
pub fn check_root() -> bool {
    false
}

/// Whether this platform's elevation model matches the interactive
/// sudo-password-prompt flow (Unix: `sudo -S`). Windows uses UAC/Administrator
/// tokens instead, which front-ends should present very differently (there is
/// no password to type — the user must relaunch the process elevated).
pub const fn supports_sudo_prompt() -> bool {
    cfg!(unix)
}

/// Prompt for sudo elevation if not already root
/// Returns true if elevation succeeded or already root, false otherwise
#[cfg(unix)]
pub fn elevate_if_needed() -> Result<bool> {
    if check_root() {
        return Ok(true);
    }

    print_warning("System cleaners require root privileges.");
    println!("You can either:");
    println!("  1. Run this command again with sudo");
    println!("  2. Enter your password to elevate now");
    print!("\nWould you like to elevate now? [Y/n]: ");
    io::stdout().flush()?;

    let mut response = String::new();
    io::stdin().read_line(&mut response)?;

    match response.trim().to_lowercase().as_str() {
        "n" | "no" => {
            print_warning("Skipping system cleaners. Only user cleaners will run.");
            Ok(false)
        }
        _ => {
            // Try to validate sudo access by running a simple command
            print!("Authenticating... ");
            io::stdout().flush()?;

            let status = Command::new("sudo")
                .args(["-v"])
                .status()
                .context("Failed to execute sudo")?;

            if status.success() {
                println!("{}", "✓ Authentication successful".green());
                Ok(true)
            } else {
                print_error("Authentication failed. Skipping system cleaners.");
                Ok(false)
            }
        }
    }
}

#[cfg(windows)]
pub fn elevate_if_needed() -> Result<bool> {
    if check_root() {
        return Ok(true);
    }
    print_warning(
        "Some system cleaners require Administrator privileges. Restart CleanSys as Administrator (right-click → 'Run as administrator') to use them.",
    );
    Ok(false)
}

#[cfg(not(any(unix, windows)))]
pub fn elevate_if_needed() -> Result<bool> {
    print_warning("System cleaners are only available on Unix-like systems and Windows.");
    Ok(false)
}

/// Execute a command with sudo if not already root
/// This function handles terminal raw mode properly for TUI applications
/// It assumes sudo credentials are already cached (via password dialog or sudo -v)
#[cfg(unix)]
pub fn execute_with_sudo(command: &str, args: &[&str]) -> Result<std::process::Output> {
    use std::process::Stdio;

    if check_root() {
        // Already root, execute directly
        Command::new(command)
            .args(args)
            .output()
            .context(format!("Failed to execute command: {}", command))
    } else {
        // Use sudo with non-interactive mode and cached credentials
        // The -n flag prevents sudo from prompting for a password
        let mut sudo_args = vec!["-n", command];
        sudo_args.extend_from_slice(args);

        Command::new("sudo")
            .args(sudo_args)
            .stdin(Stdio::null())
            .output()
            .context(format!("Failed to execute command with sudo: {}", command))
    }
}

#[cfg(not(unix))]
pub fn execute_with_sudo(command: &str, args: &[&str]) -> Result<std::process::Output> {
    Command::new(command)
        .args(args)
        .output()
        .context(format!("Failed to execute command: {}", command))
}

/// Print a header with a colorful banner
pub fn print_header(text: &str) {
    let width = 60;
    let padding = (width - text.len()) / 2;
    let line = "=".repeat(width);

    println!("\n{}", line.bright_blue());
    println!(
        "{}{}{}",
        " ".repeat(padding),
        text.bright_white().bold(),
        " ".repeat(padding)
    );
    println!("{}\n", line.bright_blue());
}

/// Print a success message
pub fn print_success(message: &str) {
    println!("{} {}", "✓".green().bold(), message);
}

/// Print a warning message
pub fn print_warning(message: &str) {
    println!("{} {}", "!".yellow().bold(), message);
}

/// Print an error message
pub fn print_error(message: &str) {
    eprintln!("{} {}", "✗".red().bold(), message);
}

/// Ask for user confirmation
pub fn confirm(prompt: &str, default: bool) -> Result<bool> {
    let yes_no = if default { "[Y/n]" } else { "[y/N]" };
    print!("{} {} ", prompt, yes_no);
    io::stdout().flush()?;

    let mut response = String::new();
    io::stdin().read_line(&mut response)?;

    match response.trim().to_lowercase().as_str() {
        "y" | "yes" => Ok(true),
        "n" | "no" => Ok(false),
        "" => Ok(default),
        _ => {
            print_warning("Invalid response. Please enter 'y' or 'n'.");
            confirm(prompt, default)
        }
    }
}

/// Format bytes into human-readable sizes
pub fn format_size(bytes: u64) -> String {
    const KB: u64 = 1024;
    const MB: u64 = KB * 1024;
    const GB: u64 = MB * 1024;

    if bytes >= GB {
        format!("{:.2} GB", bytes as f64 / GB as f64)
    } else if bytes >= MB {
        format!("{:.2} MB", bytes as f64 / MB as f64)
    } else if bytes >= KB {
        format!("{:.2} KB", bytes as f64 / KB as f64)
    } else {
        format!("{} bytes", bytes)
    }
}

/// Get the size of a directory or file in bytes.
///
/// Implemented as a pure-Rust recursive walk (no shell-out to `du`), so it
/// works identically on Linux, macOS, and Windows — the previous `du -sb`
/// implementation relied on a GNU-only flag and silently reported `0` on
/// BSD/macOS `du`. Symlinks are not followed (their own size is counted,
/// not the target's), matching `du`'s default behaviour and avoiding
/// infinite loops on cyclic symlinks.
pub fn get_size(path: &str) -> Result<u64> {
    const MAX_DEPTH: u32 = 512;
    Ok(dir_size(std::path::Path::new(path), 0, MAX_DEPTH))
}

fn dir_size(path: &std::path::Path, depth: u32, max_depth: u32) -> u64 {
    let metadata = match std::fs::symlink_metadata(path) {
        Ok(m) => m,
        Err(_) => return 0,
    };

    if metadata.file_type().is_symlink() {
        return 0;
    }

    if metadata.is_file() {
        return metadata.len();
    }

    if metadata.is_dir() {
        // Guard against pathological/cyclic directory structures: give up on
        // descending further rather than risk a stack overflow. In practice
        // no real cache/temp/trash directory this tool targets comes close
        // to this depth.
        if depth >= max_depth {
            log::warn!(
                "get_size: max recursion depth ({max_depth}) reached at {:?}; size may be underestimated",
                path
            );
            return 0;
        }

        let mut total = 0u64;
        if let Ok(entries) = std::fs::read_dir(path) {
            for entry in entries.flatten() {
                total = total.saturating_add(dir_size(&entry.path(), depth + 1, max_depth));
            }
        }
        return total;
    }

    0
}